The process begins with a detailed analysis of eating habits using a daily food diary clients are asked to keep. Lifestyle is equally important with exercise habits, work stress and social commitments factored into the assessment. Those scared of the scales need to brace themselves for an honest weigh-in, height and body fat calculation. Since not all god's children are created equal, what is a healthy weight for one person might be considered obese for another.

The role of nutritionist often spills over into the realm of counsellor, says Khoo. 'You have to understand the way people think. Some people eat because of anger or loneliness. I encourage them to call me and talk about their feelings before they start eating to fill the void.' As a result, Khoo receives phone calls and text messages at all hours of the day and night from her 'less emotionally stable' clients. Like Tinseltown's trainers, Khoo can be whoever you want her to be - psychologist, disciplinarian and friend. 'Some clients just want to talk about their life, others need someone to tell them off when they lose control,' says Khoo. 'Some people just enjoy having someone tell them what to do.'

Private sessions with nutritionists cost from $300 to $900, depending on who you see and the level of service you require.

'The process can be as involved or as remote as you want it to be,' says Khoo. 'Some people come for a one-off advice session, while one client has visited every week for the last year.'

You can forget Atkins, South Beach, The Zone, or any of the new fad diets - a qualified dietician will never recommend limiting an entire food group. Instead, a well-rounded approach based on the food pyramid will be tailored to the individual's needs.

'Fad diets abound, with most people looking for an easier way or a miracle cure. There is no such thing,' says Vicki Gallard, a private nutrition and dietetics consultancy. 'Positive, long-term changes are needed in order to lose weight, and keep it off.'

So what about those incredible shrinking celebrities?

'Sometimes their genes are their secret,' says Gallard. 'For many of them, it is not as easy as it looks. We see the before and after pictures but not the time, effort, money, trainers, nutritionists and chefs employed to help.'

Celebrities' obsession with their appearance is more than narcissism, Gallard says. It is their job to look good.

'A million-dollar movie contract is often the motivation for losing pounds - most people don't have that sort of carrot dangled in front of them,' she says.

The light fantastic

Hongkongers spend a lot of time and money dining out.

To stop your waistline expanding as your wallet shrinks, Daphne Wu, dietician-in-charge at Matilda International Hospital, suggests:

- Don't order the combo, you'll get double the portion and double the calories.

- Choose baked, grilled or steamed over fried.

- Avoid minced and ground meats.

- Choose broth-based soups over creamy ones.

- Order dressings and sauces on the side.

- Order a starter as your main for portion control.

- Eat slowly so you know when you are full.

- Avoid sodas, juices and alcohol.